The Longwood Medical Area (LMA) of Harvard Medical School (HMS) houses the Beth Israel Deaconess Medical Center (BIDMC), Dana-Farber Cancer Institute (DFCI), Brigham and Women's Hospital (BWH), and Children's Hospital Boston (CHB), all within walking distance. Within these institutions are hundreds of Pis dedicated to modern cancer research. At the present time, however, there isn't a single small animal positron emission tomography (PET) scanner in the LMA, and the only small animal single photon emission computed tomography (SPECT) scanner has limited availability and no computed tomography (CT) capabilities. Without microPET/CT and microSPECT/CT, it is now impossible to screen transgenic animals for tumor formation and growth, to develop mouse models that replicate human cancer, or to follow therapeutic efficacy in vivo and longitudinally in the same animal. In this High-End Instrumentation Grant, we demonstrate how the purchase of a single trimodality microPET/SPECT/CT (FLEX?) scanner from Gamma Medica Ideas, Inc., in conjunction with a $1.1 M+ commitment from the BIDMC, will be able to service the needs of cancer researchers of the LMA. Siting this instrument in a central and easily accessible location at the BIDMC enables the NIH to make a significant investment that will benefit numerous NIH-funded research projects across multiple institutions. We see this as an opportunity not only to bring the best resources to our research area, but also as an opportunity to foster greater interaction among the investigators themselves. In particular, this instrument will service the Program Project Grant of Dr. Lewis C. Cantley (BIDMC), who in collaboration with Dr. Ronald A. De Pinho (DFCI), has developed novel transgenic models of cancer based on phospholipid signal transduction. Currently, these animals can only be screened at necropsy for tumor formation, which has greatly slowed progress. With the installation of the FLEX scanner, Drs. Cantley and De Pinho will be able to pinpoint the location of tumors in living animals, and follow their responses to treatment. Dr. William R. Sellers (DFCI) has developed several animal models of prostate cancer that could potentially replicate the osteoblastosis seen in humans, and with the FLEX scanner, would be able to perform high-throughput screening for this phenotype. Dr. Bruce R. Zetter (CHB), an expert on angiogenesis and tumor cell homing, would finally have a methodology to monitor neovascularization and to quantify metastatic spread in his animal models. Dr. Yolonda L. Colson (BWH), in her studies on host cell tolerance during transplantation, would be able to follow white blood cells over days to weeks in vivo. Thus, this single investment in the densely-populated LMA would fulfill the goal of PAR-05-124 by having a "significant impact on biomedical/behavioral research and contribute to the advancement of human health." [unreadable] [unreadable] [unreadable]